Both vulnerable. West deals.
Opening lead: 
4
The magic number 200 is the Holy Grail of the duplicate bridge player. To achieve that score, he will indulge in close doubles—the sort you would never make in rubber bridge. To back that up, you have to be a skillful defender.
This auction is typical of the tournament game. Since he had better than a minimum opening bid with support for his partner’s suit, and since his side obviously had the balance of power, West elected to double at his second turn. That was a dubious decision since his queen of hearts was a doubtful value. Paradoxically, the lady , turned out to be crucial for the defense.
Against one no trump doubled, West led a low spade. East grabbed his king and returned the jack, covered by the queen and taken with the ace. It was time to examine the position.
It seemed certain that declarer had a spade stopper and one of the minor-suit aces. Since the heart suit was going to produce five tricks with the help of a finesse, if declarer could take his spade trick. and the ace he would have seven tricks. Therefore, West opted to switch. But to which suitt. lie decided he would give declar-er his heart tricks. Had he chosen .to exit with a low heart, it would have been all over. Declarer would have run that to his nine, forced out the ten of spades and would still have had the ace of diamonds as an entry to his seventh trick; the good spade.
The solution was elegant: West exited with the queen of hearts. Now declarer could not use the nine of hearts as an entry to hand, for that would leave dummy’s long hearts withering on the vine. And when East gained the lead with the ace of clubs, he could lead a diamond through declarer’s tenace to establish the setting trick for the defenders.